A conventional wrench is shown on FIG. 18. Normally, a conventional wrench would have been processed with either reflexible or non-reflexible surface treatment; which means the body 20, grip 21, mark area 22, mark 221 and all other areas are either reflexible or non-reflexible. Defects of a conventional wrench are described as follows:
1. Since the surface treatment is applied to the whole set of the wrench, the mark 221 and the body 20 are in the same condition; besides, the mark area 22 is not wide enough to have bigger mark 221, therefore the mark 221 is not easy to be identified with the body 20. When an operator is working at a dim place such as inside an engine compartment of an automobile, varieties of wrenches are not easy to be identified and then operations are bothered.
2. Since the whole set of the wrench has either reflexible surface or non-reflexible surface except the two driving ends, surface of the wrench is in a flat and smooth condition without substance to create enough friction to avoid getting loose in hand when operating.
3. In manufacturing process of the wrench, the mark area 22 and the mark 221 are generally forged to form with use of jigs. After certain numbers of the forging process, the jigs are likely damaged of abrasion with the body 20, cracks are easily coming out on the edge of the mark area 22 and in between the mark area 22 and the mark 221, and then productions are fault.
The present invention is an improvement on the shortcomings of the conventional wrench described above.